Astro build benchmark: Node vs Deno vs Bun

bench-astro-final.sh

#!/bin/bash
# Astro production build benchmark across Node, Deno, and Bun.
# Creates git worktrees for isolation, runs builds sequentially to avoid resource contention.
#
# Requirements: git, node (via fnm), deno, bun, python3
# Usage: cd into your Astro project root, then run this script.

set -euo pipefail

RUNS=3
PROJECT_ROOT=$(git rev-parse --show-toplevel)
RESULTS_FILE="/tmp/bench-results.txt"
> "$RESULTS_FILE"

eval "$(fnm env)"

log() {
  echo "[$(date +%H:%M:%S)] $1"
  echo "$1" >> "$RESULTS_FILE"
}

cleanup() {
  log "Cleaning up worktrees..."
  for rt in node deno bun; do
    git worktree remove "/tmp/bench-$rt" --force 2>/dev/null || true
    git branch -D "bench-${rt}-build" 2>/dev/null || true
  done
}
trap cleanup EXIT

time_build() {
  local runtime="$1"
  local dir="$2"
  local cmd="$3"
  local times=()

  log "=== $runtime ==="

  for i in $(seq 1 $RUNS); do
    rm -rf "$dir/dist"
    log "  Run $i/$RUNS..."
    local start=$(python3 -c 'import time; print(time.time())')

    eval "$cmd" > "/tmp/bench-${runtime}-run${i}.log" 2>&1
    local exit_code=$?

    local end=$(python3 -c 'import time; print(time.time())')
    local elapsed=$(python3 -c "print(f'{$end - $start:.2f}')")

    if [ $exit_code -ne 0 ]; then
      log "  Run $i FAILED (exit $exit_code)"
      tail -20 "/tmp/bench-${runtime}-run${i}.log"
      times+=("FAIL")
    else
      log "  Run $i: ${elapsed}s"
      times+=("$elapsed")
    fi
  done

  local valid_times=()
  for t in "${times[@]}"; do
    [ "$t" != "FAIL" ] && valid_times+=("$t")
  done

  if [ ${#valid_times[@]} -gt 0 ]; then
    local csv=$(IFS=,; echo "${valid_times[*]}")
    python3 -c "
times = [$csv]
avg = sum(times) / len(times)
mn = min(times)
mx = max(times)
print(f'  RESULT: min={mn:.2f}s  max={mx:.2f}s  avg={avg:.2f}s  ({len(times)}/$RUNS ok)')
" | tee -a "$RESULTS_FILE"
  else
    log "  ALL RUNS FAILED"
  fi
  log ""
}

# Header
log "Astro Production Build Benchmark"
log "================================"
log "Date: $(date)"
if [[ "$(uname)" == "Darwin" ]]; then
  log "Machine: $(sysctl -n machdep.cpu.brand_string)"
  log "Cores: $(sysctl -n hw.ncpu) / RAM: $(sysctl -n hw.memsize | awk '{printf "%.0f GB", $1/1073741824}')"
else
  log "Machine: $(cat /proc/cpuinfo | grep 'model name' | head -1 | cut -d: -f2 | xargs)"
  log "Cores: $(nproc) / RAM: $(free -h | awk '/Mem:/{print $2}')"
fi
log ""

# Create worktrees
for rt in node deno bun; do
  git worktree remove "/tmp/bench-$rt" --force 2>/dev/null || true
  git branch -D "bench-${rt}-build" 2>/dev/null || true
  git worktree add "/tmp/bench-$rt" -b "bench-${rt}-build" HEAD
done

# Install deps (npm for all three, since Deno's own installer has Vite resolution issues)
log "Installing dependencies..."
for rt in node deno bun; do
  (cd "/tmp/bench-$rt" && npm install --silent 2>&1) | tail -1
done
log ""

# Node
NODE_VERSION=$(node --version)
log "Runtime: Node $NODE_VERSION"
time_build "node" "/tmp/bench-node" "cd /tmp/bench-node && node ./node_modules/.bin/astro build"

# Deno (npm-installed node_modules, deno as the JS runtime)
DENO_VERSION=$(deno --version | head -1 | awk '{print $2}')
log "Runtime: Deno $DENO_VERSION"
time_build "deno" "/tmp/bench-deno" "cd /tmp/bench-deno && deno run -A ./node_modules/.bin/astro build"

# Bun
BUN_VERSION=$(bun --version)
log "Runtime: Bun $BUN_VERSION"
time_build "bun" "/tmp/bench-bun" "cd /tmp/bench-bun && bun ./node_modules/.bin/astro build"

log "================================"
log "Full results saved to $RESULTS_FILE"